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This problem says business weekly conducted a survey of graduates from 30 top mba programs.
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On the basis of the survey, we're assuming that the mean annual salary for graduates 10 years after graduation is $138 ,000 with a standard deviation of $30 ,000.
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And we're supposed to assume that we take a simple random sample of 18 graduates and round all our answers to four decimal places.
00:21
The first thing we're asked to do is find the probability that a single randomly selected graduate would have the salary between $135 ,893 and $144 ,829.
00:31
And we are making the assumption here that our population is normal.
00:34
So we're going to use normal cdf in our calculator to figure this out.
00:38
And the first two values of this for normal cdf are the lower bound and the upper bound that you want the probability between.
00:44
And here that's the 135 ,893 and the 144 ,829 that we want to know the probability that we're between.
00:52
And then we follow that with the mean and standard deviation of our population.
00:57
So that's the 138 ,000 mean average and the standard deviation of 30 ,000.
01:02
And now we can evaluate this expression to get our probability in our calculator.
01:05
And we're going to round to four decimal places, which gives us 0 .1180.
01:12
And then for our next probability, this time we are dealing with the sample mean of our sample of 18...